So, I finish the deployment of a multi-server SharePoint farm, and I setup the Search Service Application; I was able to configure Search and browse the admin pages in central admin successfully. After trying to browse the search admin main page from central admin a couple of days later, I got the error message "The base type 'Microsoft.Office.Server.Search.Internal.UI.SearchFarmDashboard' is not allowed for this page. The type is not registered as safe". To resolve this I added the following line to the Central Admin web site's web.config:
<SafeControl Assembly="Microsoft.Office.Server.Search, Version=18.104.22.168, Culture=neutral, PublicKeyToken=71e9bce111e9429c" Namespace="Microsoft.Office.Server.Search.Internal.UI" TypeName="*" />
But when I clicked the Search Service Application name from searchfarmdashboard.aspx I got the error message "Code blocks are not allowed in this file." To resolve the issue, I added the following line to the Central Admin web site's web.config:
<PageParserPath VirtualPath="/searchadministration.aspx" CompilationMode="Always" AllowServerSideScript="true" />
Hope this helps!